This invention generally relates to noise suppression in an audio signal. More specifically, this invention relates to reduction of background noise of an audio signal derived from a received signal in a cellular telephone.
Some digital cellular telephones operable in a time division multiple access (TDMA) system exhibit a high level of background noise in the audio signal of received signals. This high background noise is determined to be system noise and has been found to be present in various TDMA systems operable on various frequency bands. The background noise appears during pauses or breaks in the intelligent portion of the audio signal (e.g. breaks in a caller""s speech pattern). At higher volumes settings of the cellular telephone, the user can easily hear this background noise, and this condition is unsatisfactory to the user. Hence, there is a need to reduce the background noise level while not otherwise impacting the discernible audio quality of a received signal.